In a paper, hereby incorporated by reference, entitled "Options in Gas Turbine Power Augmentation Using Inlet Air Chilling" by I. S. Ondryas et al. presented at the Gas Turbine and Aeroengine Congress and Exposition on Jun. 11-14, 1990 in Brussels, Belgium, the authors discuss the use of adsorption chillers and/or mechanical/electrical chillers for cooling inlet air in a gas turbine based cogeneration plant. Such cooling increases the capacity of the plant, particularly during peak demand periods in the summer. The cost of equipment to effect such cooling is amortized by the economic benefit gained from increased revenues derived during peak operations.
Although the paper discloses using heat contained in gases exhausted from the gas turbine to generate steam that is applied to an adsorption chilling system based on lithium bromide, or ammonia, an economic comparison is made of systems based on a centrifugal, two-stage ammonia based adsorption system, and a hybrid of these two techniques. The paper shows that, in terms of shortest payback period, a two-stage ammonia adsorption system is the most attractive.
The conventional refrigeration systems described in the above-identified article are capable of providing low temperatures for air conditioning, refrigeration, and ice making purposes, which are significantly below the minimum 45.degree. F. temperature considered suitable for inlet air chilling in a gas turbine based power plant. Inlet air temperatures lower than about 45.degree. F. should be avoided to prevent ice build-up on the compressor blades taking into account a drop of about 10.degree. F. in the static air temperature in the compressor inlet, and a 3.degree. F. safety margin. Conventional refrigeration systems to achieve these rather modest cooling goals without using chlorinated fluorocarbons (CFC's) which are ecologically damaging, and high voltage electrical components to support chiller motors, etc., are often complicated, and hence expensive, reducing the advantages of inlet air chilling.
It is therefore an object of the present invention to provide apparatus for augmenting the power produced by a gas turbine system which is simpler in design and operation than apparatus of this type disclosed in the above-identified paper.